Fort Stevens Review Published by the Friends Of Old Fort Stevens, An Oregon Nonprofit Corporation

Helping To Preserve The History Of Oregon’s Fort Stevens State Park (503) 861-1470 www.visitfortstevens.com foofs@teleport.com

Spring 2015 Three Issues: Winter, Spring, Summer

The Harbor Defenses Of The Columbia River: The Invisible Weapon

Part I

By D. Lindstrom (largely based on Marshal Hanft’s book, “Fort Stevens…”)

In cooperation with Fort Stevens State Park, the Friends Of Old Fort Stevens is funding a new interpretive panel for the kiosk at the Fort Stevens submarine mine complex. The original resulted from a donation by Dee Swindler, now deceased, who was a hard working sergeant assigned to the submarine mine program during World War II. The new panel will continue to honor him and his donation. In so doing, this two part series is an effort to pull together a rather complex story that will help isolate essential information for the benefit of visitors.

The first task is to review what I call the submarine mine complex at Fort Stevens. It may surprise some readers to realize that underwater mines were part of the original 1890’s defense plan at Fort Stevens and across the river at Fort Columbia. These mines were “controlled” from shore casemates. They were “planted” in the river in groups, all connected together with electrical cables, and separate groups were similarly connected. Individual mines were fired by an electrical charge emanating from a switch, among many, located in the on-shore submarine mine casemate.

In April 1897 as the West Battery at Fort Stevens was nearing completion Captain Fisk, US Corps of Engineers, began construction of the mine casemate on the right flank of the earthworks. Within a year’s time, it was ninety-nine percent completed. The structure was essentially a concrete box with an angled entrance, all covered with sand. It was designed to withstand a 12-inch shell blast. The electrical cables necessary to carry current to the underwater mines were contained in an enclosed gallery from the casemate to the outside edge of the sand covering. From there they were contained in an open gallery leading to the riverbank.

Fisk made a hurried, often-overlooked addition to the casemate at the outbreak of the Spanish American War in April 1898. It was nested along the east side of the angled entrance. Its purpose was to provide the added space for essential equipment that was lacking in the original casemate. The oil engine, transformer, and storage battery were placed here, all necessary to produce the direct current used to explode the underwater mines. The structure was constructed of 12x12 timbers. Both the floor and roof timbers were covered with concrete. An entrance from inside the original casemate was knocked out, and an outside entrance was provided in line with the original one. This added structure was also covered with sand. Even though later changes made this addition obsolete and both entrances eliminated, one can’t help but wonder if anything is left of it under all that sand.

West Battery, Fort Stevens State Park

In 1908 an entirely new mine casemate was constructed along the backside of the sand covered original one. Its western edge was next to the entrance of the original, concrete casemate and effectively eliminated the outside door of the April 1898 addition. Called “typical,” it was a wood frame structure. The 1908 casemate featured rooms that served either as a dormitory or office, an operating room, a generator room, and a storage battery room. Aside from being behind the sand cover for the original casemate, it had neither its own sand cover, nor was it protected from exploding shells. Submarine mine personnel were tired of the dampness in the original casemates. The advent of the military airplane corrected this irritation.

By 1910 there were new fire control innovations for aiming shore guns and for deciding which submarine mines to explode. The use of observation stations, or base end stations, was improved upon. Invisible lines were established with a station on each end. The length of the invisible line, or base line, was known. Instruments in the stations sighted the target, and by using math skills a triangle was formed, giving men in the plotting room information from which they determined the distance and speed of the target in relation to the gun or the location of submarine mines. A second innovation in range finding was an instrument called the “depression position finder” or DPF. Stations with this finely tuned device did not need a second station to form the base line. The distance between the DPF and the low tide was the base line. The distance between the DPF and the target formed the right angle, while a scale in the DPF instrument determined the second angle. Most stations had instruments allowing them to serve either an end of an invisible base line or as a single station using the DPF instrument.

Needless to say, to keep the Fort Stevens submarine mine complex up to date, a fire control/base end station was needed to house the DPF instrument and if needed, to serve as the end of an invisible base line. By March 1911, one was completed adjacent to the east end of the 1908 mine casemate. The structure looked like a stubby towboat with a tall pilothouse tower in front. The first floor served as a dormitory for enlisted men. Then the “pilothouse tower” featured three floors above the first one. Of the tower’s three floors, the first one housed the officer’s dormitory, the second the plotting room, and the third the instrument, or observation room. The third floor had a hole in the center that allowed those in the observation room to look down on the plotting board. Only the tower’s third floor had a view of the river over the top of the complex’s sand covering. The only protection this structure had was its position behind the original sand covering. Other than that it was a wood frame structure with a precise concrete instrument column for the DPF that reached from the ground through the tower to the third level.

Well, World War I changed thoughts about submarine mine casemate protection. The airplane’s use as a weapon made the 1908 casemate obsolete and in the event of war, dangerous to the occupants and the whole submarine mine project. So, in 1918 construction began on yet a fifth structure at the tightly confined Fort Stevens submarine mine complex. This one was dug into the original sand covering in front of the 1911 fire control/base end station. It featured a five-foot thick concrete roof covered with nine feet of sand. The inside walls were approximately eight feet thick, while the front of the structure had a northerly exposure with no sand berm in front of it. Things slowed down after the war, and as of mid 1921 the equipment from the 1908 submarine casemate had not yet been transferred to the new one.

Before we go any further, it is necessary to review the portion of the submarine mine project located at Fort

Stevens sister fort, Fort Columbia. Fort Columbia was across the river in Washington State. These two forts were close partners in the project. Having done that, the actual submarine mine operations will be described later. Fort Columbia’s submarine mine structures followed the same development pattern as those at Fort Stevens. Fort Columbia had the advantage of being situated on Chinook Point, which rose above the Columbia River. Thus it wasn’t threatened by high water as early Fort Stevens was.

Consequently, the first submarine mine casemate at Fort Columbia, constructed in the same time frame as the one at Fort Stevens, was buried in the ground and didn’t need a sand covering. They were approximately the same size and functioned in the same manner. No record has been found indicating that additional space was needed for the oil engine, transformer, and storage batteries as at Fort Stevens. From its location, it is assumed that at some point its cables leading into the river were in an open gallery.

Unlike the new mine casemate constructed at Fort Stevens in 1908, Fort Columbia and to wait until 1911 for its upgrade. The new submarine mine casemate was constructed behind a rocky knoll in a small cove down the hill from the original one. It too was a “typical,” wood frame structure, unprotected except for the rock knoll between it and the river. It had the same floor plan as the one at Fort Stevens. However, its position caused far less of the

electrical cable to be exposed. Chinook Point, rising high above Fort Columbia, had ideal positions for fire control/base end stations. Thus a fire control/base end station housed in a tower, as constructed at Fort Stevens, was not necessary.

Now we move on to World War I. The implications of the airplane had the same effect on the 1911 submarine mine casemate version at Fort Columbia as the 1908 casemate at Fort Stevens. However, at Fort Columbia it is apparent that the 1911 casemate was torn down so the 1921 model could occupy its desirable space. Once again, its floor plan was the same as at Fort Stevens. It too had a five-foot concrete ceiling and thick concrete walls. Apart from being dug into the rock knoll, its roof and sides were covered with soil. As with the demolished 1911 structure, its electrical cable was exposed as it entered the river. However, its exposure was far less than at Fort Stevens. At Fort Columbia, it laid across a natural low-lying rock wall rising out of the riverbank.

The shore installations for the submarine mine project were passive, in that they did not possess the means to defend either themselves or the submerged mines. The fear was that an enemy could reach them by using craft too small to justify exploding a mine. These small craft were thought capable of locating the underwater cables and destroying them. Consequently river gun batteries were constructed to eliminate the threat. In the beginning, 3-inch rapid-fire guns on balanced pillar mounts were installed on both sides of the river: Battery Smur at Fort Stevens and Battery Crenshaw at Fort Columbia. Soon more batteries were added. Fort Stevens: Battery Freeman with two 6-inch guns on balanced pillars and another 3-inch gun, Battery Pratt with two 6-inch guns on disappearing carriages. Fort Columbia: Battery Murphy with two 6-inch guns on disappearing carriages. Fort Canby, at the mouth of the river on the Washington State Side: Battery O’Flying with two 6-inch guns on disappearing carriages, Battery Allen with two 6-inch guns. Battery Allen’s position gave allowed it to open direct fire on an enemy vessel attempting to enter the river’s mouth. Within a few years the three-inch guns were eliminated along with Battery Freeman and Battery O’Flying.

Now, why were submarine mine casemates needed on both sides of the river? In the early days there were two

channels, the north channel and the south channel. The south channel, considered the more important one, was controlled at Fort Stevens while the north channel was controlled at Fort Columbia. Electrical cables then connected mines with their designated mine casemate. This arrangement remained in place until the winds of war began to blow in the late 1930’s. It is important for the reader to realize that between the Spanish American War and Pearl Harbor the only time mines were planted and connected to cables was for practice. Other than that all the mines, miles and miles of cable, and other equipment were stored on shore, most notably at Fort Stevens. During the Spanish American war cables were laid in the river but sources conflict as to whether or not mines were planted. One source relates that the “south, main channel in front of Fort Stevens was closed with four groups of mines.” If they were, it was for a very short duration. The threat during World War I was seen as minimal and although no mines were permanently planted, much attention was given to practice.

After World War I and up to 1921 some aspects of mine planting practice took place each year. After that, practice was somewhat spasmodic until the mid 1930’s. Mine planters were not readily available, and only when one called upon the Harbor Defenses of the Columbia was the entire process of cable laying and mine planting practiced. After each practice all the cables and mines were taken up and stored at Fort Stevens.

As the 1930’s wore on, it became apparent that active mine casemates on both sides of the river was not desirable. Fort Stevens was practically at the high tide level and its long cable gallery leading to the riverbank was open for all to see, thus subject to sabotage. On the other hand, Fort Columbia sat on Chinook Point with the 1921 mine casemate closer to the river behind a substantial rock knoll. Planners realized that with a bit of work, electrical cables leading from the casemate could be completely covered as they entered the river on their way to the submerged mines. This was deemed a critical factor. Furthermore, from Fort Columbia cables would not have to be strung across the entire width of the river and subject to strong currents. They could land at near by Sand Island and from there connect to shorter cables leading out to the mines themselves. By 1937 the decision was made. The one and only submarine mine casemate would be at Fort Columbia while all the support supplies, equipment, planting vessels and hardware would remain at Fort Stevens. The switch was completed sometime between late 1940 and early 1941.

The Summer 2015 issue will conclude the story of the INVISIBLE WEAPON.

THE FRIENDS OF OLD FORT STEVENS UNDERGOES A MAJOR MEMBERSHIP STRUCTURAL CHANGE The FOOFS board of directors conduced the announced membership meeting on January 28, 2015 at Camp Rilea. The question before the members was whether or not FOOFS should become a NONMEMBER nonprofit corporation. The rational was that fewer and fewer members were able to attend the annual membership meetings. After a period of questions and discussion the vote was taken. The majority voted that FOOFS should become a NONMEMBER nonprofit corporation. As related earlier, the FORT STEVENS REVIEW will

continue to be mailed out to the current mailing list. This issue will be posted on the FOOFS website as will all future issues. The annual FOOFS picnic will take place as planned on September 19, 2015. The picnic reservation form will be included in the SUMMER 2015 Review issue. The FOOFS board of directors anticipates that by the time of the picnic, they will be ready to introduce an HONORARY FOOFS MEMBERSHIP program. This membership program will also be introduced on the FOOFS web site. It is hoped that this new membership initiative will garner additional members and that the annual picnic will continue.

One of several docks at Fort Stevens that serviced the Submarine Mine Project and the Quartermaster. The triangle affair in the center is the target towed passed gun batteries and submarines mine stations for target practice.